Oil-well-casing cementing shoe



E.V. CROWELL.

OIL WELL CASING CEMENTING SHOE.

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APPLICATION FILED MAR. 9| 192|.

E. V. CROWELL. OIL WELL CASING CE'MENTING SHOE.

APPLICATION FILED MAR. 9, 1921.

Patented Oct. 17, w22.

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` i WIM/8858 E. V. CROWELL. OIL WELk CASING CEMENTING SHOE.

. APPLICATION FILED MAR. 9. 192|. 1,432961?, Patented Oct. 17, E922,

, 3 SHEETS-SHEET 3. 5 l! Y ze?? g A A www Patented Oct. 17, 1922.

l I S ERD V. CROWELL, OF TULSA, OKLAHOMA.

OIL-WELL-CASING CEMENTING SHOE.

Original application led June 15, 1920,.Seria1 No. 389,151. Divided andthis application led March 9, 1921. VSerial No. 451,032.

To all whom t may Concern Be it known that I, ERD V. CiiowELL, a citizenof the United States, and a resident of Tulsa, in the county of Tulsaand State of Oklahoma, have invented certain new and useful Improvementsin Oil-Well-Oasing Oeinenting Shoes, of which the lfollowing is aspecification.

`My invention relates to improvements in well casings, particularlythose of the type employed in oil and gas wells,l and it consists in theconstructions, combinations and arrangements herein described andclaimed.

One of the foremost objects of the invention is to provide a cementingshoe for use in connection with an oil or gas well cas- .ing, by meansof which a cementiiig mixture, as for example mud-fluid, can be ejectedfrom the lowerinost section or oil string to fill the space between thefoil string and well bore and thus seal the formation seat against theseepage of water.

A further object of the invention is to provide a cementing shoe for oilor gas well casings, which offers the distinctiveand exclusive advantageof providing means for placing a cementing mixture behind the oil stringwhile the well is expelling oil and gas and the casing is resting on itsformation seat.

A further object of the invention is to provide means for introducing acementing mixture into the. space between. the oil string and wall ofthe hole, without having to first plug the hole beneath the casing,raise the casing or work against the high pressure of the oil and gas.

A further object of the invention is to provide -means in oil or gaswell constructions, enabling the making of a water-tight seal betweenthe casing and rock formation independently of the casing shoe on thelowermost extremity of the oil string or the texture of thel landingformation on which the shoe rests.

A further and important object of the invention is to provide means,including a valve mechanism forming part of the well casing, enablingplacing a mud-fluid or other ceiiienting mixture behind the oil stringwhile it is resting on its formation seat, and oil and gas are beingexpelled through the casing.

Other objects of my invention will appear in the followingspecification, reference bein had to the accompanying drawings, in w.ich

Figure l is a longitudinal section illustrating the casing cementingshoe and its associated parts in the operative position in the oilstring of a well casing, said casing being shown resting on itsformation seat near the bottom of the bore.

Figure 2 is a detail sectional View illustrating the mudding packer inthe approximate position to have the upper and lower packer rubbersexpanded against the cementing shoe,

Figure 3 is a similar View, taken at right angles to the section inFigure 2, illustrating the mudding packer in the operative f positionopposite. the mud valves in the cementing shoe, f

Figure 4 is a detail side elevation of the mudding packer before therubbers are expanded, the supporting slips at the bottom being showndisassembled for purposes of illustration,

FigureI 5 is a detail longitudinal section of' the cementing shoe withlits mud valves,

Figure 6 is a detail horizontal section on the line 6 6 of Figure o,showing how the.

mud valves ai'e mounted,

Figure 7 is a detail plan View of the rubber-expanding spider, and

Figure 8 is a detail horizontal section taken substantially on the line8-8 of Figure 4, and showing the springs and associated parts of thesupporting slipsz This is a division of my co-pending application forLetters Patent for oil well casing cementng shoes, filed June l5, 1920,Serial No. 389,151.

In order that the reader might be able to more fully appreciate thepurpose of the invention, it is thought well to preface the descriptionof the construction and mode of operation by a brief description and gaswell casing operation. Casing, as now used in oil field operation, ineither iron of the oil :icoI

or steel tubular pipe, the kinds and sizes A complete column of pipe orcasing as placed in the bore of oil wells, is commonly referred to asthe string of casing. rlhe fundamental purpose of the oil well casing isthat of protection, that is to say, to keep the water and other foreignsubstances from falling into the shot hole at the bottom and therebyeither crowding the oil back from the bore or obstructing the lower endof the bore in such a manner that neither oil nor gas can flow.

The problem of water exclusion from oil wells is merely that ofinserting a string of water-tight casing, so that its bottom is tightlylodged below the lowest water-bearing stratum and above thetop oftheproductive oil sand, thereby s'ealing the water off from descentbelow the casing, thus preventing water originating above from invadingthe productive oil or gas sands below.

ln drilling oil or gas wells, the formations passed through as the depthincreases consist of alternating`layers of lime-stone, shale, andoccasionally a stratum of sand. The Shale layers predominate over thelime layers as regards number and thickness, and again the lime layers`predominate over the sand layers in the same manner. Usually thelunderground water finds its channels of flow in the lime or sandstrata, the water flowing through the sand stratum generally above orbelow a lime stratum.`

As the depth of the hole is increased during the drilling operation,water producing lime or sand strata are encountered, the

water thus released by the puncturing of the strata by the drill point,settling in the hole and filling it with Water. The drilling operationsare thus greatly retarded, due to the cushioning effect the water has onthe drilling operation of the tools.

Again, the water released from the lime strata washes down over theshale strata below, causing the -shale to cave, slough out .and falldown the hole. A loose shale formation may thus cave to such an extentas to even entirely bury the tools. An enormous amount of additionalwork is required in thereafter excavating the material and recoveringthe tools.

Referring to Figure 1, it is obvious that for the casing to successfullyperform its function of protecting the shot hole, in the productive oilor gas sand, as represented at O, from being flooded with water thatoriginates in the strata above the casing seat S, it is necessary thatthe casing shoe 2 make a positive water-tight seal or bond with the rockformation at S.

lhen the casing has been landed on its format1on`seat S and the casingshoe 2 has made a positive water-tight seal with the i formation seat S,it is said to .have made a shut-off, as commonly referred to. Thepresent day methods of effecting a positive water-tight seal between thecasing shoe 2 and the formation seat S, separate themselves into twomain classifications', the formation shut-off and the cement shut-off.

Formation shut-off is the term commonly applied to the operation ofexcluding water, where the casing, with a shoe of some kind, is landedor driven into a stratum of shale or clay, using no artificial bond.Cement shut-ofi1 is the term commonly applied to the operation ofexcluding water, where cement or mud-Huid is used to form a bond betweenthe casing and the formation in which the shoe of the casing is landed.

Formation conditions, and texture of the landing formation are oftensuch that the .casing shoe 2 is prevented from making a seal or bondwith the formation seat S. Consequently, water finds its way down aroundthe casing shoe 2, and the casing l thus fails in its primary functionof protecting the productive oil or gas sand from being flooded withwater from above, commonly referred to as top water.

It is generally conceded by those experienced in the art, that `the onlymeans of providing a water-tight bond or seal between the casing and theformation, independent of mechanical packers, is by the application ofcement or mud-fluid behind thecasing and above the casing shoe 2. It isthe prime purpose of the device to provide means of placing cement ormud-fluid behind the casing of oil or gas Wells in a way more ex-`pedious than is commonly practiced, and

at the lowermost extremity resting on an annular projection of rock orother material, commonly known as the formation seat S. The bore of thewell merges with the opening O in the stratum of oil or gas sand,commonly known as the shot hole.

The very first consideration is to produce a water-tight joint or bondbetween the casing shoe 2 and the formation seat S. In order that theneed of the invention may be more fully appreciated, and a particularand exclusive advantage more thoroughly understood, it is thought wellto explain the method, now practised, of placing a sealing materia-lbehind the .casing of oil or gas wells.

Therefore, digressin brie-fly from the description of the invention, itis Well to bear in mind that'the method, no w practised, is

to insert or Abuild a temporary plug in the the introduction of thesealing material through the casing. l

After the temporary plug is thus in place, and the oil and gaseffectually sealed in, the sealing mater-ial is then introduced throughthe casing where it falls on top of the plug,

' when it is necessaryv to lift the casing from its .format-ion seat soas to let the sealing material out into the annular space between thecasing and wall of the bore.v After the sealing material has beenforcedvfrom the casing, with a column of water above, to fill theannular space outside the casing, the' casing is again let down, and thetemporary plug in the hole drilled out.

` Now, due to a heavy internal sand pressure and consequent violentexpulsion of oil and gas, under heavy pressure, it is often impossibleto insert or build a temporary plug beneath the formation seat S, andabove the oil or gas sand, as such a procedure requires, Aside from theimpossibility of ap-` plying a sealing material by this method, in' manyinstances, it offers the disadvantage of having to suspend productionfor a time.

lt is also regarded `by those experienced inI the art, that. thequestion of determining just when the casing is lifted from itsformation seat, and just when the cementing material has been forced outof the casing to fill the annular space outside of the casing, offersone of the most perplexing problems in the application of this method,the accurate determination of which is necessary for assurance of itssuccessful operation.

By referring to Figure 1, a particular and exclusive advantage of myinvention may be observed, whereby means are provided for theintroduction of a sealing material through the tubing 25, while oil andgas is being expelled through the casing 1, exterior of the tubing 25,thus obviating the necessity of having to temporarily plug the well in,or raise and lower the casing.

Reverting now to the description of the invention: There are two majorparts of which vitv is constituted, namely, the cementing shoe 3, andthe mud packer 4. The cementing shoe 3 is very much like one of thesections of the well casing, it being in fact, joined. to one of them bythe coupling 5 in Figure 1. Both ends are threaded; one for the coupling5 and the other for the bowl 6, which in turn is very much like anordinary coupling since it has the same eX- ternal and internaldiameters.

Two or more valves 7 normally close ports 8 in the annular enlargement 9of the shoe 3, each being held in place by rather powerful arcuate leafsprings 10, which are secured to the shoe at 11. The springs occupy anannular groove 12 and are sheltered therein by the overhanging parts ofthe enlargement 9. l

Either the flange 13 or a series of projections in the same place, whichwould accomplish the same purpose, support the mud packer'4 in the bowl6 of the cementing shoe, by virtue of the engagement of the slips 14therewith. These slips are segmental as shown in Figures 4 and 8, havingkeeper slots 15 shaped to suit the keys 16 on the slip cage 17. Recesses18 in the slips 14 accom' modate springs .19 which force the slipsoutwardly into contact with the adjacent wall.

The c-asing bowl 6 is machined from a steel forging and when thusmachined is provided with a tapering portion 20 which aids incontracting the slips 14 when pulling the mud packer 4 out of thecasing. The

surfaces of the slips 14 are slightly convexed to facilitate thewithdrawal of the mud packer. The adjusting ring 21 on the lower end ofthe shell of the packer 4, abuts the slidable packing mechanism on theshell to lift said mechanism out of the casing upon withdrawingthepacker.

The upper threaded end of the packer I shell carries the collar 22, intowhich the spider 23 is screwed, the legs 24 of the spider resting on thecollar. The mud tubing 25 is screwed into the spider from above, whilethe delivery tube 26 is screwed into the spider from beneath. But byvirtue of the fact that the delivery tube is integrally joined to thepacker shell 4 at the right angled outlet extension 27, it would be morenearly correct to say that the spider 23 is screwed onto the deliverytube 26.

There are two packer rubbers on the shell 4; the upper rubber 28 islocated below the collar 22, the other rubber 29 below the mudluiddistributor ring 30. This ring has an annular concavity 31 which readilypermits the mud-Huid to flow toall outlet valves 7 from the point ofdischarge 27. The distributor ring 30 is slidable on the shell 4 and hasa slot 32 which enables relative movement of the ring in respect to theoutlet 27 without obstructing the outlet.`

A base ring 33 provides the foundation for the lower packer rubber 29,in that the lower packer rubber employs the base ring as an abutmentagainst which to expand, and in that the base ring holds the lowermostrubber out of the casing bowl 6. llt is necessary that the lowermostrubber 29 expands against the shoe 3 slightly below the discharge valve7, the parts of the mechanism being so proportioned that this actherubbers 28 and 29 are gradually compressed and expanded against the wallof the shoe 3, while the discharge outlet 27 ultimately finds 'aposition in line with the valve 7.

It is important that particular attention be called to valves 7, uponwhich depend the practical value and possible operation of theinvention; it is to be understood, therefore, that modifications andchanges as to their 'particular design and number may be made withoutdeparting from the spirit of the invention. l

The operation may now be easily followed. As the well drilling operationprogresses and various water-beauang strata are encountered, sections ofpiping are let down. These become progressively smaller as the depth ofthe well increases, and the uppermost ones are known as water stringsfAs mentioned above, the lowermost section of piping is known as the oilstring, and a portion thereof is shown in Figure 1. The lcasing shoe 2is solely for the purpose of imparting strength to the-oil string andkeep it from crimping due to the enormous weight .imposed thereon. It isvery seldom that a satisfactory joint forms of its own accord betweenthe shoe 2 and the formation seat S. A mud seal meets all requirementssatisfactorily.

The cementing shoe 3 is introduced in the. casing l at the desiredlocation from the bottom, the mud-fluid outlet valves 7 being normallyheld closed by the leaf springs 10. The tubing 25 with lits mud packermechanism 4 is lowered into the casing, the slips 14 rubbing against thecasing walls by virtue of the springs 19 behind them, until theyencounter the supporting ledge 13 near the bottom of lthe casing bowl 6.

1t is the weight of the tubing 25 on the spider 23 and associated parts,whereby the upper and lower rubbers 28 and 29 are caused to expand fromthe positions in Figures 2 and 5 to that shown in Figures 1 and 3. Theyform a perfect seal between the shell 4 of the packer and the shell 3 ofthe shoe, the concavity 31 of the mud distributor ring 30 constitutingan annular channel which leads the mud fluid to the two or moredischarge valves 7.

,1t is of utmost importance to observe that while mud-fluid lis beingpumped through the tubing 25, gas and oil are. enabled to es- Cape upthrough the casing but around the tubing. The pressure of the mud fluidopens the valves 7 so that the material flows out into the space betweenthe casing and the wall of the bore B, filling all crevices andexcluding the water which flows from water bearing strata, from thecasing of the well. Naturally, none of this water can seep into the shothole O because of the secure seal around the shoe 2. If desired, mudfluid may be pumped Iin until it overflows at the top, and when the sealis completed, the mud packer 4is withdrawn by pulling on the tubing 25.

`While the construction and arrangement of the improved casingceIhe'nting mechanism as herein described and claimed, is that of agenerally preferred form, obviously modifications and changes may bemade without departing from the splirit of the invention or the scope ofthe claims.

I claim l. A well casing resting on its formation seat in a well boreopen to a productive stratum, and means forming one of the sections ofthe casing, including valve mechanism enabling the ejection of seallingmaterial from inside of the casing into the space between the casing andbore, while fluid flows through the casing from said productive stratum.2. The combination of a well casing, and means located in the casing forconducting sealing material to a point of discharge in the wall of thecasing, in a direction opposite to that of the fluid flow in the casingwithout obstructing it.

3. The combination of a well casing, and

its formation seat in a bore opened to a productive stratum, a conduit4on the interior of the casing conducting sealing material in thedirection opposite to the flow of fluid from the stratum withoutobstructing said flow, and a valve apparatus embodied as a section ofthe casing, through which the sealing materiial from the conduit isejected into the space between the casing and bore. to Aform a tightjoint around the formation seat.

4. The combination of a well casing and its formation seat in a boreopened to a productive stratum-a conduit on the interior of the casingconducting sealing material lin the direction opposite to the llow offluid from the stratum without obstructing said flow, a valve apparatusembodied as a Section of the casing, through which the sealmg materialfrom the conduit is ejected into the space between the casing and bore,and f cementing shoe embodied as one of the .cas- .j

ing sections, with a plurality of valved' ports a delivery tubeinteriorly of the casling for conducting sealing material to said ports;and means operatively assocla-ted with a part of said tube for securinga tight joint against the casing above and below said ports.

6. The combination of a well casing, a cementing shoe embodied as .oneof the casing sections, with a plurality of valved ports; a delivery'tube Iinteriorly of the casing lfor conducting sealing material to saidports; means operatively associated with a part of said tube forsecuring a tight joint against the casing above and below said ports,and means for circumferentially distributJing the sealing material tosaid portsv from the discharge of said tube.4

7. The combination of a Well casing, a cementing shoe embodie'd as oneof the cas-` ing sections, with valved. ports; tubing interiorly of t-hecasing conducting sealing material to said ports, includling a packenshell spaced from the casing but enabling the passage of iiuid throughthe casing while the sealing material flows in said tubing; and packingmeans in the space between said shell and casing forming a tightjoint-above and below salid valved ports.

8. The combination of Aa well casing, a cementing shoe embodied as oneof the casing sections, with valved ports; tubing interiorly of the`casing conducting sealing material to said ports, including a packershell spaced from the casing but enabling the passage of fluid throughthe casing whilethe sealing material flows in said tubing; packing meansin the space between said shell and casing forming a tight joint aboveand below the valved ports, and a ring surrounding the packer shell andformingan abutment for said packer means, for distributing the sealingmaterial to said ports.

9. The combination of a well casing, with a cementing shoe having aplurality of valved ports; tubing interiorly of the casing forconducting seallng material to the ports, including a packer shellspaced from the casing and slightly movable relative thereto; a ringsurrounding said shell for distributing the sealing material to allports, including a slot preserving communication of the tubing outletduring said shell movement; a ring bridging the slot at the upper end ofthe distributor` ring, packer means in the space between the shell andcasing, abutting the bridge and distributor rings; and means carried bythe shell and tubing for expanding the packer means to form a tightjoint above and below said valved ports.

10. r1`he combination of a well casing, a cementing shoe coupled in thecasing, with a plurality of valved ports; tubing interiorly 'of thecasing conducting sealing material to said ports, including a packershell capable of slight movement in respect to the casing; packer meanson the shell to form a tight joint above and below said ports, and meanscarried by the shell engageable by a portion of the casing at apredetermined place to constitute an abutment against which said packermeans expand.

ll. The combination of a well casing, including a cementing Shoe withy aplurality of valved ports, and a casing bowl with a supporting ledge;tubing inside the casing conducting sealing material to said ports. andincluding a packer shell capable of slight movement in respect to thecasing; normally contracted pac-ker means carried by the shell, formaking a tight joint between the shell and casing above and below saidports, and means carried by the shell engageable 'with said supportingledge to constitute an abutment against which said packer means eX- pandduring said slight movement of the shell.

1.2. The combination of a packer shell, with a slip cage; a casing bowlin respect to which the packer shell has slight movement, including a.supporting ledge; and slips carried by the cage, with sprlngs forpressing the slips against the wall of the casing bowl thereby to engagethe ledge and provide an abutment.

13. The combination of a packer shell, with a slip cage having recessesand keys, a casing bowl in respect to which thel packer shell has slightmovement, including a supporting ledge; and slips occupying therecesses, with openings receiving the keys for limiting the outwardmovement of the slips, including springs urging the slips into contactwith the bowl wall as the packer shell moves downwardly, said slipsfinally engaging the ledge to form an abutment.

14. The combination of a cementing shoe, with a series of valved ports,and an attached casing-bowl of an internal diameter larger than that ofthe shoe, including a supporting ledge; and a packer shell spaced fromthe shoe, with upper and lower packer rubbers in said space, andabutment means engageable with the ledge, against which said rubbersexpand to form tight joints.

15. The combination of a well casing, including a cementing shoe with aseries of valved ports; and tubing for conducting sealing material tothe ports, with an integral packer shell spaced from the casing f andcarrying upper and lower packer rubbers, and a spider and collarrespectively carried by the tubing and shell, for expanding the rubbersat the sides of the ports by virtue of the weight of the tubing.

16. The combination of a well casing with a Xed abutment and a series ofvalved ports; tubing in the casing for conducting sealing material tothe ports, made integrally with a packer shell spacedly located from thecasing; an abutment carried by and movable with the shell intoengagement with said fixed abutment` packer rubbers respectively aboveand below said series of ports in the space between the shell andcasing, and means including a spider, mutually car-` ried by the tubingand shell for imposing the weight of the tubing on the rubbers to expandthem into tight engagementwith the casing, the lowermost rubber abuttingthe movable abutment through a. base ring.

17. The method of sealing wells, consisting of lowering a well casinginto permanent engagement with the formation seat near the bottom of abore. and introducing sealing material into the bore around the casingWithout stopping the flow of Huid through the casing.

18. The method of sealing wells, consisting of lowering a valved wellcasing into permanent location on the formation seat of a bore, andintroducing sealing material into the casing to flow out of the Valveand ll the surrounding bore.

ERD V. CROWELL.

